From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5536 invoked by alias); 20 Jan 2005 14:57:53 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 5519 invoked by alias); 20 Jan 2005 14:57:50 -0000 Date: Thu, 20 Jan 2005 14:57:00 -0000 Message-ID: <20050120145750.5518.qmail@sourceware.org> From: "rguenth at tat dot physik dot uni-tuebingen dot de" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20041201143906.18754.pinskia@gcc.gnu.org> References: <20041201143906.18754.pinskia@gcc.gnu.org> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug tree-optimization/18754] unrolling happens too late/SRA does not happen late enough X-Bugzilla-Reason: CC X-SW-Source: 2005-01/txt/msg02811.txt.bz2 List-Id: ------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-20 14:57 ------- Subject: Re: unrolling happens too late/SRA does not happen late enough > Note PR 18755 blocks this if we go the SRA after loop optimization which > seems like a better idea. I do not completely understand this sentence ;) I argue that SRA after loop is a bad idea, because SRA, in my testcases, will expose new oportunities for selecting ivs, so we'll need to run another loop after SRA. So I chose for loop0 sra loop instead of sra loop sra loop which is one pass less. Also with -ftree-early-loop-optimize we get in .vars for PR18755: ;; Function float foobar() (_Z6foobarv) float foobar() () { : return a.array[3] * b.array[3] + b.array[2] * a.array[2] + b.array[1] * a.array[1] + a.array[0] * b.array[0] + 0.0; } which is what we want? Or do we now just paper over another problem here? I'm confused... Richard. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18754